Ignition apparatus



July 2o 1926. 1,593,339

F. C. KROEGER IGNITION APPARATUS Filed sept. 18. 1924 Patented July 20,1926.

UNITED sTArEs 1,593,339 PATENT OFFICE.'

FREDERICK C. KROEGER, OF ANDERSON, INDIANA, ASSIGNOR T GENERAL MOTORSCORPORATION, A CORPORATION OF DELAWARE.

IGNITION APPARATUS.

Application led September 18, 1924. Serial' No. 738,531.

This invention relates to electrical ignition apparatus forinternal-combustion engines and, more particularly, to the constructionof the ignition timer.

One of the objects of the present invention is to secure sparkingimpulses in more rapid succession than heretofore. In the presentinvention this is accomplished by reducing the weight of the timerbreaker lever to the lowest possible amount while still maintaining asubstantial degree of rigidity and byA locating plane of contact of thetimer contacts at an angle to a normal to the arc of movement ofthemovable contact.

Another object of the invention is to improve the manner of adjustingthe stationary timer contact.

A further object is to improve the manner of connecting the breakerlever and condenser with the ignition timer terminal.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing. wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 of the drawings is a plan view of the ignition timer without thedistributor rotor and distributor head; Fig. 2 is a side view partiallyin section of the ignition timer distributor; Figs. 3, 4, 5 and 6 aresectional views on the lines 3 3, 4-4, 5--5, and 6-6, respectively, ofFig. 1; Fig. 7 is a plan view of the termi-nal plate of the ignitiontimer.

In the drawings, 2() designates a cupshaped ignition timer housing whichsupports for rotation, a cam shaft 21, upon which is mounted a timer cam22 (see Fig. l) and a distributor rotor 23, (see Fig. 2). The timer cupsupports a plate 24, attached by screws 25; and plate 24 supportsdistributor head 26 carrying a center contact 27 and a circular row ofposts 28 which cooperate with the rotor 23, in the usual manner.

The plate 24 is provided with a bearing flange 30 which provides abearing for a breaker lever plate 31 having a handle 32 extendingthrough a notch 33 provided in the side of the bearing plate 24. Plate31 is maintained upon a plurality of arcuate bearing bosses, which areshown in section at 34 in Fig. 2, by means of studs 35, attached toplate 31 and extending through slots 36 provided in bearing plate 24.The studs 35 receive nuts 37 for the purpose of causing a plurality ofresilient dished washers 38 to bear upwardly against a plane washer 39,which in turn is pressed against the undersurface of the bearing plate24.

Plate 31 supports a stud 40 having a shoulder 41 and a reduced portion42 which together provide a bearing for the non-con- 65 ducting hub 430ibreaker lever 44. Lever 44 comprises top and bottom iange members I 45and 46, joined by a web member 47. AThe flanges 45 and 46 are providedwith holes in alignment for receiving the hub 43. The hub 43 is securedin position by a clip 48 engaging a groove 49 of the stud 40.

The cam 22 cooperates with an L-shaped rubbing block having one leg 50located in the path ot movement of the cam and having the other leg 51located between the breaker lever flanges 45 and 46. and attached by asingle rivet 52 to the web 47. The free end of lever 44 makes asubstantial angle with the plane of that portion of the web to which therubbing block is secured. The outer end of the web portion 47 carries atimer contact 53 for engaging a stationary timer contact 54 attached toan adjusting screw 55, threadedly engaging a clamp bracket 56 at- 85tached by screws 57 to the breaker plate 31. The clamp bracket 56includes a portion looped around and threadedly engaging the contactscrew 55. One branch 58 of this loop is apertured to receive a clampingscrew 59 which threadedly engages the other branch 60 of the clampingloop. The distributor head 26 being removed from the bearing plate 24,adjustments of the timer i contact 54 can readily be made by turning thescrew 55 with a screw driver or small wrench and then clamping the screw55 in position by means of the screw 59. This construction has beenfound to be more satisfactory than a construction wherein the 100 timercontact adjusting screw is locked in position by a lock nut.

The breaker plate 31 insulatingly supports a terminal plate 6l, which issecured by clamping between non-conducting plates 62 m5 and 63 by rivets64, which are secured to the plate 31. Plate 6l is provided with holes65 which are considerably larger than the rivets 64; and the plates 62,63 and 31 are provided with holes but slightly larger in diameter H0than the rivets 64 and located in alignment with the holes 65. The plate61 carries a post 66 for receiving a screw 67 for attaching to the plate61 a resilient spring conductor 68 and a conducting strap 69.

The spring conductor 68 extends between the flanges 45 and 46 of thebreaker lever 44 and is attached to the web 47 by the same rivet 52which secures the rubbing block in position.

The strap 69 is attached by screw 70 to the insulated condenser foilwhich is located within the condenser case 71. The grounded condenserfoil is connected with the interior of the case 71. The condenser isattached to the plate 31 and grounded thereon by a clip 72 soldered tothe case 71 and attached to the plate 31 by a single screw 73. Turningof the clip 72 is prevented by providing a recess in the plate 31 andreceiving the arcuate portion of the clip -72, as shown in Fig. 3.

The insulated terminal plate 61 is provided with a threaded hole 804erreceiving a screw 81 for attaching a wire leading to an ignition coil.

The lever 32 is provided with a hole 82 for receiving a link or othersuitable mechanism attached to a lever by which the timer plate mav bemanipulated from the drivers seat.

The plane of contact of contacts 53 and 54 is at a substantial angle toa normal to the chord of the arc of movement of the movable contact 53.A slight rubbing of movable contact upon the stationary Contact takesplace tending to keep the contacting surface clean, and enabling thetimer to operate satisfactorily at higher speeds than when this plane isnormal or substantially at right angles to this chord. The angle of theplane of contact to the normal to the chord of the arc of movement ofthe movable contact is preferably about 9 degrees for the breaker levershown. This angle may varyaccording to theV dimensions of the breakerlever, and may be little less or greater than this angle. ne of thecontacts may be crowned or slightly spherical instead of plane withbeneficial effects. It is believed that the relatively high speedoperation of this present timer is due to small mass of the lever 44,and the location of the' contact surface of the contacts 53 and 54 withrespect to the arc of movement of contact 53.

While the form of embodiment of the present invention as hereindisclosedpconstitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

qWhat lI claim is as follows:

1. An ignition timer including a cam, a breaker lever of channel sectionwith channel web located substantially parallel to the cam axis, anL-shaped rubbing block having one leg thereof extending into the path ofmovement of the cam Lind the other leg located against the channel weband between the channel flanges, a leaf spring having one end attachedto a stationary part, and having a portion extending between the rubbingblock and the lever, and a single rivet securing said rubbing block andleaf spring to the lever.

2. An ignition timer including a timer housing, a breaker' platerotatably supported by the housing and having an arm extendin@ from thehousing, a breaker lever insu atingly supported by the plate, and aterminal plate insulatingly supported by the breaker plate and having aportion thereof within the housing electrically connected with thebreaker lever and a portion located exteriorly of the housing andadjacent the breaker lever arm for receiving a wire-attaching device.

3. An ignition timer including a timer housing, a breaker platerotatably supported by the housing and having an arm extending from thehousing, a breaker lever insulatingly supported by the plate, and aterminal plate insulatingly supported by the breaker plate and having apost located within the housing and a wire receiving portion extendingexteriorly of the housing, and a leaf spring conductor connecting saidpost with the breaker lever. Y

In testimony whereof Iv hereto atx m signature.

FREDERICK C. KROEGER.

